CVE-2026-30835: parse-server Malformed `$regex` Query Leaks Database Vulnerability

MODERATE
Advisory Identifier: GHSA-9cp7-3q5w-j92g
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CWE-209
Published
Advisory Summary

CVE-2026-30835 is a MODERATE malformed `$regex` query leaks database vulnerability (CWE-209: Generation of Error Message Containing Sensitive Information) affecting parse-server libraries in the npm ecosystem. The issue involves malformed `$regex` query leaks database error details in api response. Remediation is available by upgrading affected packages to version 9.5.0-alpha.6, 8.6.7.

CVE-2026-30835 at a Glance

CVE Identifier CVE-2026-30835
GHSA Identifier GHSA-9cp7-3q5w-j92g
Severity MODERATE
CVSS v3.1 Base Score N/A
CWE Classification CWE-209: Generation of Error Message Containing Sensitive Information
Affected Product parse-server
Package Ecosystem npm
Published Date
Last Updated

How to Fix CVE-2026-30835

To remediate this vulnerability, upgrade all affected parse-server dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

parse-server fixed: 9.5.0-alpha.6 
npm install parse-server@9.5.0-alpha.6
parse-server fixed: 8.6.7 
npm install parse-server@8.6.7
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

npm ls parse-server

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2026-30835, inspect your project dependencies using npm:

npm ls parse-server

Analyze the terminal output to locate any version of parse-server in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 9.5.0-alpha.6), your application is affected.

Note: The npm ls parse-server command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-209: Generation of Error Message Containing Sensitive Information, where the product generates an error message that includes sensitive information about its environment, users, or associated data. In parse-server, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Impact A malformed $regex query parameter (e.g. `[abc)` causes the database to return a structured error object that is passed unsanitized through the API response. This leaks database internals such as error messages, error codes, code names, cluster timestamps, and topology details. The vulnerability is exploitable by any client that can send query requests, depending on the deployment's permission configuration. ### Patches The fix sanitizes database error objects so that only a generic `"An internal server error occurred"` message is returned to clients, while the detailed error is logged server-side. The fix respects the `enableSanitizedErrorResponse` server option. ### Workarounds There is no workaround other than upgrading. The error leakage occurs in the query execution layer and cannot be mitigated through server configuration or client-side changes. ### Resources - GitHub security advisory: https://github.com/parse-community/parse-server/security/advisories/GHSA-9cp7-3q5w-j92g - Fix in Parse Server 9: https://github.com/parse-community/parse-server/releases/tag/9.5.0-alpha.6 - Fix in Parse Server 8: https://github.com/parse-community/parse-server/releases/tag/8.6.7

CVE-2026-30835 Affected parse-server Versions

2 component(s)
Fixed Versions:
9.5.0-alpha.68.6.7
Product / Package Ecosystem Affected Versions Fixed Version
parse-server
npm/parse-server
npm
≥ 9.0.0
< 9.5.0-alpha.6
9.5.0-alpha.6
parse-server
npm/parse-server
npm
< 8.6.7
8.6.7

References

GitHub Advisory / Wiki ADVISORY
https://github.com/parse-community/parse-server/security/advisories/GHSA-9cp7-3q5w-j92g
NVD — CVE-2026-30835 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-30835
parse-server Source Repository REPOSITORY
https://github.com/parse-community/parse-server
parse-server Release RELEASE
https://github.com/parse-community/parse-server/releases/tag/8.6.7
parse-server Release RELEASE
https://github.com/parse-community/parse-server/releases/tag/9.5.0-alpha.6

Frequently Asked Questions

What is CVE-2026-30835?
CVE-2026-30835 is a security vulnerability in parse-server involving Malformed `$regex` query leaks database error details in API response under CWE-209: Generation of Error Message Containing Sensitive Information.
Which parse-server versions are affected?
Affected versions include releases prior to 9.5.0-alpha.6, 8.6.7 across affected packages: parse-server.
What version fixes CVE-2026-30835?
Upgrading to 9.5.0-alpha.6, 8.6.7 (or the latest patched release for your respective branch) resolves the vulnerability.
Is parse-server affected?
Yes, parse-server is affected in releases prior to 9.5.0-alpha.6, 8.6.7. Upgrade your dependency to 9.5.0-alpha.6, 8.6.7 or later.
What CWE is associated with CVE-2026-30835?
CVE-2026-30835 is classified under CWE-209: Generation of Error Message Containing Sensitive Information (The product generates an error message that includes sensitive information about its environment, users, or associated data.).
How can I check npm dependencies for CVE-2026-30835?
Run the dependency tree command: 'npm ls parse-server'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-9cp7-3q5w-j92g",
  "modified" : "2026-03-06T23:25:13Z",
  "published" : "2026-03-06T23:25:13Z",
  "aliases" : [ "CVE-2026-30835" ],
  "summary" : "parse-server: Malformed `$regex` query leaks database error details in API response",
  "details" : "### Impact\n\nA malformed $regex query parameter (e.g. `[abc)` causes the database to return a structured error object that is passed unsanitized through the API response. This leaks database internals such as error messages, error codes, code names, cluster timestamps, and topology details. The vulnerability is exploitable by any client that can send query requests, depending on the deployment's permission configuration.\n\n### Patches\n\nThe fix sanitizes database error objects so that only a generic `\"An internal server error occurred\"` message is returned to clients, while the detailed error is logged server-side. The fix respects the `enableSanitizedErrorResponse` server option.\n\n### Workarounds\n\nThere is no workaround other than upgrading. The error leakage occurs in the query execution layer and cannot be mitigated through server configuration or client-side changes.\n\n### Resources\n\n- GitHub security advisory: https://github.com/parse-community/parse-server/security/advisories/GHSA-9cp7-3q5w-j92g\n- Fix in Parse Server 9: https://github.com/parse-community/parse-server/releases/tag/9.5.0-alpha.6\n- Fix in Parse Server 8: https://github.com/parse-community/parse-server/releases/tag/8.6.7",
  "severity" : [ {
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    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N"
  } ],
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    "type" : "ADVISORY",
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    "type" : "PACKAGE",
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  }, {
    "type" : "WEB",
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  }, {
    "type" : "WEB",
    "url" : "https://github.com/parse-community/parse-server/releases/tag/9.5.0-alpha.6"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-209" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-03-06T23:25:13Z",
    "nvd_published_at" : "2026-03-06T21:16:17Z"
  }
}